Turning and thread-milling machine.



A. M. THOMSON.

TURNING AND THREAD MILLING MACHINE.

APPLICATION FILED DEC.26. I916.

Patented Sept. 17, 1918.

4 SHEETS-SHEET I.

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TURNING AND THREAD MILLING MACHINE.

APPLICATION FlLED DEC.26|1916.

PatentedSept. 17,1918.

4 SHEETS-SHEET 2.

A. M. THOMSON.

TURNING AND THREAD MILLING MACHINE.

APPLICATION FILED umze. 1916.

1 ,2'79,()@ 1 Patented. Sept. 17, 1918.

4 SHEETS-SHEET 3.

ATTORNEY A. M. THOMSON. TURIHNG AND THREAD MILLING MACHINE.

APPLICATION FILED DEC;26, 1916.

Patented Sept. 17, 1918.

4 SHEETS-SHEET 4 flz/w (All/EN nm ATTORNEY sas arsnr pr ce. i 'i TURNINGeAND THREAD-MILLING IMACHINE.

To all whom it may concern:

Be it known t-hat I, Anrnsn Monnrs THOM- soN, a subject of the King of Great Britain, residing in Newark, New Jersey, have invented certain new and useful Improvements in Turning and Thread-Milling Machines; of which the following is a specification. I 1 I My invention aims to provide a machine and methodwhich is specially applicable to the producing of screw threaded rods of large diameter and great length, although the invention may be applied to other kinds of threading work.

The accompanying drawings illustrate one embodiment of the invention.

Figure 1 is a plan, largely in section, of a machinefor taking bars of large size and great length and turning them and milling long threads thereon; i

Fig. 2 is aside elevation of the same; a

I Fig. 3 is a section on'the line *33 of Fig. 1; x

Fig. 4 is a section approximately on the line 44 of Fig. 1; r V

Fig. 5 is a section on the line 5---5 of Fig. 4;

' Fig. 6 is a partial plan anda partial section of one of the milling cutters and its driving connections;

Fig. '7 is a section of the same;

Fig. Sis a plan view of thesame; V

In Fig. 1 the rod A is shown in starting position; and in. Fig. 2 in final position.

Referring to the particular embodiment of the invention illustrated the workpiece A is a long bar orrod of large diameter which is to be turned with a lathe tool to an accurate cylinder and to be threaded throughout its length" or for a considerable portion thereof. It runs over a supporting roller B and through a sliding chuck C. thence through a rotating-turning head D which carries lathe tools or cutters E and which is mounted in a bearing block F, thence through an adjustable steady rest G and through a chuck H of special design which rotates the rod while permitting a free longitudinal feed "thereof, thence through thread milling cutters .l and K arranged in two sets. the first for roughing and the second for finishing;

and finally the threaded end of the work passes through a feed nut formed of two half nuts Land over a supporting roller The rod is fastened in the chuck C with its left hand or forward end projectin'g ap Specification 10f Letters Patent.

Application-filed December 26, 1916. Serial No; 138,940.

Patented Sept. 17, 1918.

proximately to the lathe head D, with the chuck in its retracted position, atthe right. The Chuck is then fed slowly forward carrying the end of the rod through the lathe head and the steady rest'G. The feeding chuck is-thenunclamped from the rod and shifted back to its starting position and again clampedon the rod and fed forward, carrying the end of the rod to the roughing thread cutters. The chuck C' is again retracted, clamped on the rod and advanced, and this operation feeds the rod through the roughing and finishing thread cutters and into engagement with the lead nut L. Thereafter the chuckC is released andis no longer used on the same'rod. Aft-er the-end of the rod entered the rotating chuck iH it was rotated thereby simultaneously with its forward feed by the chuck C, and a thread was cut'by reasonof this rotation. As soon therefore as the threadedend of therod engaged the lead nut L, itscontinued rotation caused a corresponding feed and the original feeding chuck C could be thrown out of use. The chuckC may be of any usual or suitable construction. As illustrated, thehead N clamps directly on the work and is mount} ed on a large hollow spindlerotating in the body of the chuck andcarrying at its rear end a worm gear 0 which is slowly rotated by a worm P (Fig. 2) on across shaft Q which driven from a worm of ordinary type adapted to slide on a longitudmal shaft'jR driven as hereinafter described. The base of the chuck is mounted to slide on guidesS and is provided at one side with a split nut T adapted to be engagedor disengaged from a feed screw U which is driven through suit able intermediate gearing at the-rear end from the shaft R as indicated by dotted lines in Fig. 1. The gearing described is arranged to give a comparatively slow rotation and a comparatively fast feed. Of course, it will be designed in accordance with the pitch of the thread or threads to'be cut. And the pitch will generally be greater for a triple thread (for which theillustrate'd machine is designed) than for a double'or a single thread. I I

I The turning head D is driven by means of a worm gear V in engagement with a worm W (Fig. 2) on a cross shaft X driven by bevel gears from the shaft R so as to secure a comparatively fast rotation and to makethe proper fine turning cuts.

The steady rest G has jaws which form-a bearing through which the shaft can pass and turn freely. It is of the usual style, arranged in two parts mounted to slide on the base Y as indicated in Fig. 3 and adjustable toward and from each other to embrace or release the work by means of a shaft Z having reversely threaded portions engaging the opposite halves of the bearing, the shaft being operated by hand by means of a crank on the end.

The chuck H is mounted in bearing blocks a and h set on the bed Y of the machine and carries a worm gear 0 in engagement with a worm on a cross'shaft'cl, Fig. 2, by which it is rotated at the same rate as the first feeding chuck C.

This chuck'H, however. is held against longitudinal movement and is specially designed to permit the work to move longitudinally through it. The construction is illustrated in detail in Figs. 4L and 5. The oasing of the chuck is divided transversely into two parts, united by bolts 0, with a hollow space between them in which are located certain sharp edged rollers f designed to grip the work "A and to rotate the same as the chuck is rotated; and at the same time to guide the work and permit its longitudinal movement. The rollers f are on shafts g mounted in bearing blocks h arranged to slide radially in the casing and each block 7L carries fast in it a nut jengaged by a screw in having an outer squared end Z for turning it to any desired position of adjust- IllBllt. The severalscrews 7c carry pinions m which engage a common annular gear n. By turning any one of the screws an identical movement is imparted to them all, and all the gripping rollers f are identically adjusted inward or outward."

The thread milling cutters are shown in transverse planes for clearness. But they will be set at a slight angle to the work. corresponding to the pitch of the threads. To cut a single thread they would be located one in advance of another. But for cutting a triple thread, as illustrated, their centers will lie in transverse plane. each being set at the angle of the threads. To secure the desired variations they are mounted to be adjustable, first, radially of the work for varying the depth of the out; second. angularly according to the angle of the thread; and third, longitudinally of their axes according to the position of the thread or the space between successive threads.

There are three roughing millingcutters J arranged at equal distances around the work as indicated in Fig. 3, one immediately above and the other two' at the side of and below the work. For clearness sake the upper cutteris omitted from Fig. 1 and-the side cutter omitted from Fig. 2. The mounting of the cutters to permit the desired adjustments is indicated in Fig. 3 and, in. more detail, in Figs. 6, 7 and 8. A triangular frame 0 is fix d on the base Y of the machine and the cutters are mounted in carriages movable in radial grooves in this frame. The carriage 19 is guided on a dovetailed guide (Fig. 8) on the frame oso as to move in a radial direction and carries a nut q through which passes a screw '1 having a squared outer end by which it may be turned to adjust the carriage inward or outward. The carriage p, in turn, carries on a longitudinal guiding rib at the top a second carriage s and the latter is provided with a nut 0' through which passes a screw 10 which can be turned by its squared outer end to adjust the carriage s in a longitudinal direction. The bearing block 2) through which the spindleof the cutter passes is mounted by a central pivot w on the longitudinal adjustable carriage s. The carriage '8 has an annular groove 03 at its rearend in which travels a clamping bolt 1 By loosening the latter the bearing can be swung about the'pivot 'w to the desired position of'angular adjustment and then clamped in this position. The turning of the spindle 2 of the cutter is effected by means of a jointed flexible shaft connected with a certain amount of longtudinal play to the spindle to" permit the stated adjustments of the cutter. The shaft comprises aforward end piece 11 with a sliding key engagement with the spindle, a universal joint 12, an intermediate section 13 and a rear endpiece 14: having a sliding connection with the section 13 and connected by a universal joint 15 with the hub of a gear 16. The gears 16 are mounted on the bearing block F. Two of them are driven by a pinion 16 on a shaft. 17 at one side of the machineand the third is opera'tedsynchronously with'the other two byan intermediate pinion-18 on the other side of the machine. It is advisable to have the special chuck H which rotates the work as near to the cutters as possible- To secure this relation at the same time with a good drive for the milling cutters the flexible shafts diverge from the rear ends of the cutter spindles to the gears 16 which are in rear of the special chuck. the forward end of the latter even being tapered to get'it closer to the cutters. The shaft 17 is the main shaft of the machine which is driven by cone pulleys 19 from a belt and not only operates the milling cutters as described but, by suitable intermediate gearing whichris unnecessary to illustrate drives the various other shafts and movable parts.

Between the roughing cutters J and the finishing cutters K there is a second steadyrest 20 similar to that shown at-G ands-up ported on. the baseofthe machine and adjusted by a threaded shaft 2]. operated by a hand crank.

..;-The finishing" cutters K are mounted in play and are attached t;the

identically as described ,for

hearing .block 26 gears which i these being tapered as .indicated to permit the nut to set within the cutter shafts 24 and asiclosei to ,thecutters as possible. The two halves .areimounted on a {dove-tailed guide rib onthe base of the machine andare adjusted toward and away from each' other to clamp or to;releasegthe-work by means of r a transverse threaded shaft 27 operated by a-hand-crank at-one end. I

The engagement of-the leadnut directly with a-portionof-theithread. on the work presents a substanti-al advantage in the cutting of long threads ion rodsof :large diameter, say for producing a threaded rod. six or eight ,in'ches in diameterand from fifty to :one hundred feet long as extreme cases. Large screws of consider able length have-heretofore been made piecing togethershorter lengths, but it is almost impossible to securea perfectly accurate continuation of ztheithreadacross the joints. Where a traveling chuck :alonejis used (or traveling cutters alone) to 1 secure.

the feed a number of successive .forward ceding movements (with inte-rmedlate returns to the startingposition) must be made unless the machine be: made of an inconvenientand perhaps impractical length; and at each SHCCQSSIVQStQP there 1s. a break. in the 7 perfect continuity of-"the:thread. im-

proved apparatus .may be made comparatively short and; compact and, therefore, more accurate thana machine of great length and at the same. timewill secure a thread of uninterrupted perfection ion a rod of innlimitedlengthr .The first part of the thread, which issecuredby means of a-short feed, can be .very {perfectly made and the remainder of the threadiwill be absolutely continuoustherewithand of the same perfection throughout its length. In this connection the advantage will be seen of arranging;

the feed nut which is to engage the finished thread of thework as close toithe thread cutters as possible, so that the initial portion of the-thread-shall present the minimum variation from absolute perfection.

therefore,

' or slower within Similarly the thread cutters shouldbe as closeas possible tothespecial chuck fOlIO- tating therworltin order to shortenlthe total distance to thefeed nut and to hold thework upto the cutters with the least torsion. v fter the traveling chuckis out of usethe rotation of the .work is by means of [this special chuck. The direction of the several drives issuchthat the turning tools tendto rotate the shaft in onedirection .and the opposite direction. That is, these opposing forcestend to rotate; the work andthe rotating chuck has only to accelerate or retard such rotation sufficiently to maintain the proper rate. Furthermore the resultantirotation produced; by this chuck may. be faster considerable limits since, whatever the rate of rotation, the fQBdfIIUt will secure a proper relation-between that and. the longitudinal movement. c 7

The present machine is;advantageous as compared witha machineof tl1e- .-full-length of thethread, because of difficulties arising from heat-expansion. In the ordinary style 7 of machine the heating of the rod after the cutting operation commences necessitates moving one of the lathe headsor centers back. Asthe cutter moves farther andrfarther away. from the fixeduend of the rod the thread becomes less and less accurate. In the 'presentimachinethe fixed point isgthe feed the threadingoperation. On a long-rod the turning'tools may becomedull and require renewing before the end; of the thread' is cut. For such cases, in order tochange tools with out stoppingthe work, the turning, head may be arranged Eforad-justment along ways 8 or the likeystarti-ng ina. rear' (tothe right) position and holding its position normally, but; adjustable forward so that the tools may be changed before the uncut portion of the rod again reaches them.

, Other apparatus than. that illustrated may be used for first forming a section of the thread on the end of the rod, using only the lead screw and thread cutters as illustrated, or others of equivalent type, either the special'rotating chuck illustrated or some other means for rotating'the work while permitting it to be advanced by reason of its engagement with the feed nut. For example, a separate short rod provided with the design of thread required may be oined to the end of the work and used,:by its passage through the feed nut, to draw the work through the thread cutters and finally through the feed nut itself; so that the model thread will be duplicated on the end'of the work and will then be continuously repeated along the length of the work.

In fact various modifications may be made in the design and arrangement of the separate parts of the apparatus and the various parts may be combined in a complete machine as illustrated or may be used separately or in various other combinations by those skilled in the art without departure from the invention which is defined in the following claims.

' What I claim is l 1. A thread milling machine for milling threaded rods of great length including in combination radially and angularly adjustable rotary thread milling cutters a longitudinally-movable feeding meansand a stationary feed nut adapted to engage a portion of the thread.

2. A thread milling machine for milling threaded rods of great length including in combination longitudinallyunovable means for giving the work an initial advance and a lead nut adapted to engage a finished portion of the thread and give the work a further advance.

3. A machine for making threaded rods including in combination a rotary lathe head tending to rotate the work in one direction, thread milling cutters tending to rotate'the work in the opposite direction and a rotating chuck for rotating the work at the desired rate.

4 A machine for making threaded rods including in combination a rotary lathe head tending to rotate the work in one direction, thread milling cutters tending to rotate the work in the opposite direction and a rotating chuck for rotating the work at the desired rate and a stationary lead nut engaging the finished'thread to feed the work in proportion to its rate of rotation.

r 5. A thread milling machine'for milling threaded rods of great length including in combination a longitudinally movable feeding means to initially rotate and feed the work and a stationary feed nut arranged to engage the finished portion of the thread,

and subsequently feed the work in proportion toits rate of rotation.

6. A thread milling machine for milling threaded rods of great length including. in combination a feed nut nuts L, a radially and angularly adjustable rotary thread milling cutter, and an adjustable chuck H which rotates the work while permitting longitudinal movement thereof.

7. A thread milling machine for milling threaded rods of great length including in combination a feed nut formed of two halfnuts L, a thread milling cutter, a chuck H which rotates the work while permitting longitudinal movement. thereof and a sliding chuck C. I

8. A thread milling machine for milling threaded'rods of great length including in combination a feed nut formed of two halfnuts L, a chuck H, two sets of thread milling cutters located between said feed nut and said chuck, and driving means for said cutters comprising shafts extending from one set to the rearof said chuck and from the other set beyond said feed nut.

9. A thread milling machine for milling threaded rods of great length including in combination afeed'nut formed of two half-' nuts L, a thread milling cutter, a chuck H which rotates longitudinal movement thereof, a sliding chuck C and a rotating lathe head between the chuck C and the chuck H.

10. A thread milling machine including means for advancing the work in an axial direction, arotating chuck having a plurality-of radially adjustable disks therein with axes located in a transverse plane adapted to engage the workand rotate it the work while permitting formed of two halfwith the chuckwhile permitting it to ad- 1 vance longitudinally thr'ough'the chuck and means for simultaneously adjusting said disks. 4 I 11. A chuckfor threading machines comprising a plurality of means for gripping the work, said gripping'means being rotatable about'an axis in a plane transverse to the axis of, the work, means for simultaneously adjustingsaidplurality of gripping means, and meansfor rotating said gripping means and the work about the axis of the 1 work.

12. A thread milling machine including in combination a milling cutter mounted for angular adjustment on a base which is adjustable toward and away from the work, means for rotating the work while permitting the longitudinal movement thereof and separate means for advancing the work.

In witness whereof, I have hereunto signed my name. i 1

ALFRED MORRIS THOMSON.

Copies of this patent may he obtained for five cents each, by addressing the Commissioner of Patents. A Washington, D. G. 1 I 

